This invention relates generally to universal joints. More particularly, it relates to a universal joint which incorporates a unitary face seal and retainer assembly for retaining lubricant in the bearing area and for excluding contamination therefrom.
Universal joints used in automotive applications generally, and construction and agricultural applications in particular, often must operate under severe environmental conditions. If excessive wear is to be prevented in such applications, the bearings associated with such joints must be kept adequately lubricated. in addition, they must be protected from contamination by foreign matter.
In the past, various forms of seals were developed in an effort to prolong the operating life of universal joints. These prior seals were not satisfactory, primarily because they did not seal sufficiently well to retain lubricant and exclude contamination. Even with frequent lubrication, it was found that foreign matter entered the bearing area and caused wear at an unacceptably high rate. Attempts also were directed toward development of so-called permanently lubricated seals intended to provide perfect sealing. However, it was found that rapid wear and resulting universal joint failure occurred in these prior seals as well. Prior seals generally were of the lip type, as space limitations precluded the use of face seals. Also, stack-up tolerances inherent in universal joint assembly resulted in a working range that generally was considered to be excessive for face seals.
Further, prior seals often were crushed during final assembly of a typical universal joint. Also, for shipment and during installation of the universal joints, there often was the necessity to provide some external mechanism for retaining the bearing blocks on their associated spider trunnions.
There remains a need in the art to provide a simple, inexpensive unitary seal and retainer assembly for a universal joint, which assembly will effectively increase the working life of the universal joint. The assembly preferably should incorporate a face seal, should prevent crushing during assembly, and should retain the associated bearing block during shipment and installation.